1. Field of the Invention
The present invention relates to a heat-dissipating device, and in particular to a heat-dissipating device, whereby manufacturing cost is saved and heat resistance is reduced.
2. Description of Prior Art
Currently, heat pipe is a heat-conducting element widely used in electronic apparatuses and electronic elements. In general, the interior of the heat pipe is filled with a heat-conducting medium of good flowability, high heat of vaporization, low boiling point and stable chemical properties, such as water, ethanol, acetone or the like. The inner surfaces of the heat pipe are usually formed with a wick structure having a lot of protrusions.
In operation, one of the heat pipe acts as an evaporating section connected to a base of an electronic element, and the other end of the heat pipe acts as a condensing section assembled with a plurality of heat-dissipating fins. With this arrangement, when the evaporating section of the heat pipe is heated, the heat-conducting medium located in the evaporating section is vaporized to absorb a lot of latent heat of evaporation. As a result, the temperature of the base can be lowered. Then, the vapor-phase heat-conducting medium diffuses to the condensing section. The vapor-phase heat-conducting medium condenses into its liquid phase to release a lot of latent heat of condensation and flows back to the evaporating section through the wick structure. The heat-dissipating fins assembled with the condensing section dissipate the latent heat of condensation to the outside.
Please refer to FIG. 1, which is an exploded perspective view showing a conventional heat-dissipating device. The heat-dissipating device 3 is constituted of a heat sink 31 having fins, a base 32 and at least one heat pipe 33. The heat sink 31 has a heat-absorbing portion 311 and a heat-dissipating portion 312. The heat-absorbing portion 311 is adhered to the base 32. One end of the heat pipe 33 is disposed between the heat-absorbing portion 311 and the base 32. The other end of the heat pipe 33 is disposed through the heat-dissipating portion 312. The heat-dissipating device 3 is brought into thermal contact with the base 32 to absorb the heat generated by a heat source 4. The heat is conducted from the base 32 to the heat sink 31 and the heat pipe 33, and then the heat is conducted from the heat pipe 33 to the heat-dissipating portion 312 of the heat sink 31. By this structure, the heat-dissipating efficiency of the whole heat-dissipating device can be improved.
The base 32 of the conventional heat-dissipating device 3 has the following functions. The base 32 is combined with the heat sink 31 to directly conduct the heat to the heat-dissipating portion 312 of the heat sink 31. Further, one side of the base 32 is provided with at least one groove 321 for allowing the heat pipe 33 to be received in and combined with the heat sink 31 because the heat pipe 33 is formed into a cylindrical pipe and unable to contact the heat source 4 properly. With the base 32 being brought into thermal contact with the heat source 4 to absorb the heat generated by the heat source 4, the heat can be conduct from the base 32 to the heat sink 31 and the heat pipe 33.
Since a gap is inevitably formed between two connected heat-dissipating elements, heat resistance is generated between these two heat-dissipating elements. In order to reduce the heat resistance, these two heat-dissipating elements can be soldered together by electrical-conductive solder. However, when a plurality of heat-dissipating elements is assembled together, the heat-dissipating efficiency of the whole structure is insufficient. On the other hand, it takes more time to assemble the plurality of heat-dissipating elements together, which undesirably raises the manufacturing cost.
Further, the combination of the base and the heat sink makes the whole heat-dissipating device bulky and unable to be moved easily. Also, such a large-sized heat-dissipating device occupies more space, so that the application thereof is limited.
According to the above, the conventional heat-dissipating device has drawbacks as follows: (1) higher cost; (2) more working hours for assembly; (3) unable to be used in a smaller space; and (4) low in heat-conducting and heat-dissipating efficiency.